1. Field of the Invention
The present invention relates generally to data processing and, more particularly, to systems and methods for performing route lookups for packets of information.
2. Description of Related Art
Routers receive data on a physical media, such as optical fiber, analyze the data to determine its destination, and output the data on a physical media in accordance with the destination. Routers were initially designed using a general purpose processor executing large software programs. As line rates and traffic volume increased, however, general purpose processors could not scale to meet these new demands. For example, as functionality was added to the software, such as accounting and policing functionality, these routers suffered performance degradation. In some instances, the routers failed to handle traffic at line rate when the new functionality was turned on.
To meet the new demands, purpose-built routers were designed. Purpose-built routers were planned and constructed with components optimized for routing. They not only handled higher line rates and higher network traffic volume, they also added functionality without compromising line rate performance.
A purpose-built router may include a number of input and output ports from which it transmits and receives information packets. A switching fabric or other transmission medium may be implemented in the router to carry the packets between the ports. In a high-performance purpose-built router, the switching fabric may transmit a large amount of information between a number of internal components. Typically, the information is transmitted within the router in discrete quantities, or “cells,” which it generates by breaking down information packets that it receives.
These cells may be routed through the switching fabric or to certain output ports based on a route lookup that is performed by a routing unit. Although the routing units in the first purpose-built routers met the demands of the network at that time, they will not be able to meet the rising demands for bandwidth and added functionality as line rates and network traffic volume increase.
Thus, there is a need in the art to more efficiently implement route lookups within routers.